Two things I think should be retained from the current system: Basic skills and the 3 variants basic'd to unlock the actual skill trees.
- The Basic skills are not that unbalancing to new players and are a logical extension of your Mechwarrior becoming more familiar with his machine
- The three variant rule is purely business. This is an FtP game so there has to be a reason to buy Premium time and Mechbays. Call it a necessary evil if you must, but it really does make people experiment with new builds.
As for the trees themselves I delved into Sarna to find out what roles canon Mechs typically fill and this is the list I've come up with:
- Scout/Recon - skills would focus on speed, agility, and sensor range
- Electronic Warfare/Information Warfare - the anti-Scout role, protect from LRM/Arty/Airstrike and minor combat buffs to help fight off Scouts, improved ECM function
- Raider - Speed, agility, and damage. Could also include capture bonuses for game modes with those win conditions
- Brawler - Armor/structure increases, minor speed increases, damage and/or cooldown buffs, torso twist range/speed increase
- Direct Fire Support - Minor armor/structure increases, improved sensor range, improved optics (zoom)
- Indirect Fire Support - Faster target lock, improved spread on LRMs, minor speed increase
- Commander - Provide bonuses to lance for targeting and target acquisition, carry extra consumables, minor speed boost
This would also be limited to the number of skills you could apply to a Mech, say pick one primary tree and one secondary tree. Every two skills in your primary allows for one in your secondary. To go back to the Raven example I take a 3L with Scout primary and Raider secondary. I've sacrificed some of the utility of my ECM to create a Mech that excels at finding the enemy, reporting their position, then either rejoining the group or attempting to grab an objective behind them.
Mastery should be retained, I think the extra module slot is a nice capper for the whole progression.
Obviously some trees are more useful for pugging while others would find their niche in CW and/or tournament play.
Just some thoughts that have been rattling around in my head, if the community likes them we can keep the list above updated with suggestions and improvements.